The present invention relates in general to coating technology. More particularly, it relates to a method for forming a material capable of forming a microstructured surface on an object and the material formed thereby.
The wettability of solid surfaces is a very important property, and is governed by both the chemical composition and geometrical microstructure of the surface. Currently, hydrophobic surfaces with water contact angle higher than 130° are arousing much interest because they will bring great convenience in daily life as well as in many industrial processes. Various phenomena, such as sticking snow, contamination or oxidation, are expected to be inhibited on such a surface.
An important application for these hydrophobic surfaces is making self-cleaning coatings based on their water and dirt repellency. These self-cleaning coatings not only provide value-added products with a high potential to save on cleaning and other maintenance cost, but also are good for the ecobalance of the coated product, since cleaning chemicals no longer pollute the water and since energy is saved by reducing or eliminating maintenance cycles.
Conventionally, super-hydrophobic surfaces have been produced mainly in two ways. One is to create a rough structure on a hydrophobic surface, and the other is to modify a rough surface by materials with low surface free energy. Up to now, many methods have been developed to produce rough surfaces, including solidification of melted alkylketene dimer, plasma polymerization/etching of polypropylene in the presence of polytetrafluoroethylene, microwave plasma-enhanced chemical vapor deposition of trimethylmethoxysilane, anodic oxidization of aluminum, immersion of porous alumina gel films in boiling water, mixing of a sublimation material with silica or boehmite, phase separation, and embossing. To obtain super-hydrophobic surfaces, coating with low surface energy materials such as fluoroalkylsilane is often necessary.
The invention is generally directed to a novel method for making coating materials capable of forming a hydrophobic, microstructured surface, which may be used to make self-cleaning coatings.